Cyclically loaded structures include wind turbines, bearings, bolts, blades, rivets, screws, and the like. As used herein, “cyclically loaded” structures complete a circle of rotation around an axis, and, as they are in operation, they are subjected to variable loading, i.e., an uneven amount of pressure, torque, and resistance at different locations on the circle of rotation. Cyclically loaded structures are vulnerable to several failure modes, such as fatigue cracking, delamination, pitting, corrosion, self-loosening, and accidental damages. These failure modes are of special concern in the wind turbine industry, which is a large and growing business.
Although some of the failure modes may be effectively detected via automatic monitoring systems using well known accelerometers or strain gages, the technical problem of detecting structural damage often requires a technician to be present at the wind turbine. Therefore, regular inspections, performed by a technician, are generally established to monitor damage of sensitive components of the wind turbine.
Accordingly, improvements to Structural Health Monitoring (SHM) systems are desirable. Specifically, technologically improved Structural Health Monitoring (SHM) methods and systems for identifying structural damage are desirable. Furthermore, other desirable features and characteristics of the present disclosure will become apparent from the subsequent Detailed Description and the appended claims, taken in conjunction with the accompanying drawings and this Background.